In the winter, household activities, such as cooking, showering and doing the laundry, generate moisture that can damage the attic insulation and building materials of the roof. In the summer, attic temperatures can rise to over 150° F., which can cause premature aging and cracking of wood and roofing materials. These elevated temperatures can also increase cooling costs for the home owner. In the construction of rooves, therefore, it is often desirable to provide a ventilation opening at the roof ridge and cover it with a vent. Ridge vents are passive ventilation systems which provide openings through which air can convectively flow to and from under the roof structure to provide ventilation.
Ridge vents typically cover any elongated opening, such as one that is formed in a roof and that extends along the peak of the roof, with the opening typically being in the range of about 10–20 cm in width and running along a substantial portion of the roof peak. Typical ridge vents include “shingle-over roof ridge vents” and exposed roof vents. See for example U.S. Pat. Nos. 6,361,434; 6,233,887; 6,450,882; 6,260,315 and published U.S. application 2002/0100232A1, all of which are incorporated herein by reference.
Many ridge vents have been developed that are made of polymeric materials that are flexible along a longitudinal axis in order to permit the ridge vent to conform to the sloped sides of a roof to cover the ridge opening. These ridge vents typically include a plurality of vents and supporting structures that depend from a common panel and that serve both the functions of resisting entry of precipitation, insects, and foreign manner, while providing supportive structures that lift the panel away from the roof and provide crush resistance. It is further desirable that ridge vents have means to create a “Venturi effect” or air draft to draw hot air outwardly from the underlying attic.
Prior art roof ridge vents are known that can be rolled for compact packaging and transport to an installation site. However, to make these ridge vents rollable requires some sacrificing of thermal efficiency in drawing hot air from the underlying attic, or costly modifications to the baffle structure in order to allow the ridge vent to be rolled in a spiral form. See U.S. Pat. No. 6,233,887 col. lines 50–61 and col. to lines 45–55.
Accordingly, there remains a need for a ridge vent, and particularly a rollable roof ridge vent which can be made cost-effectively, and which efficiently assists convection of heat and moisture from beneath a roof.